Apparatus for altering the body temperature of a patient

ABSTRACT

An apparatus for adjusting the body temperature of a patient comprises an enclosure defining an interior space for receiving at least a portion of a patient&#39;s body therein. The enclosure is adapted for substantially sealingly enclosing the portion of the patient&#39;s body within the interior space with the enclosure. Heat transfer liquid may then be circulated through the interior space of the enclosure via an inlet and an outlet for flow over the patient&#39;s body in direct liquid contact therewith to promote heat transfer between the patient&#39;s body and said heat transfer liquid. The heat transfer liquid may be either warmer or cooler than the patient&#39;s body temperature, to either warm or cool the portion. Controlled cooling may be employed to induce therapeutic hypothermia, while controlled warming may be employed to counteract unintended hypothermia. The apparatus further comprises a portable control unit that includes a liquid delivery system, a power source, a control system and a user interface for powering and controlling the liquid delivery system.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.10/193,635, filed Jul. 11, 2002, now U.S. Pat. No. 6,969,399.

BACKGROUND OF THE INVENTION

This invention generally relates to medical apparatus for altering thebody temperature of a patient and more particularly to apparatus thatenables efficient, quick control of the body temperature of a patient,especially to induce hypothermia.

Sudden cardiac arrest remains a serious public health issue.Approximately 350,000 individuals are stricken in the United Statesannually, with overall survival rates of roughly 5 percent. Even withthe immediate availability of the most advanced care currentlyavailable, including cardiopulmonary resuscitation (CPR), drugs,ventilation equipment, and automatic external defibrillators, a survivalrate of 25 percent may be the probable best case scenario. Improvedtherapies to deal with this condition are clearly needed.

Numerous incidences of recovery following accidental hypothermia andcardiac arrest have been reported. This observation has led researchersto consider therapeutic hypothermia as a possible treatment for reducingthe adverse consequences of circulatory arrest. Various studies haveshown that moderate systemic hypothermia (approximately 3-5° C.(5.4-9.0° F.)) can reduce damage to vital organs, including the brain.Hypothermia induced both during and following cardiac arrest hasdemonstrated this benefit. The use of cardiopulmonary bypass has alsobeen effective in rapidly achieving this goal. Direct flushing of cooledfluids into the arterial system has also been employed with success.Both invasive measures, however, require large bore intravascularcatheters and rapid introduction of sterile solutions into the patient.Such invasive approaches have obvious disadvantages in dealing without-of-hospital emergencies.

Noninvasive cooling, if sufficiently effective and portable, would be apreferable approach. Direct cooling of the head alone has producedvariable results. However, post-resuscitative cooling of the entire bodyto approximately 33° C. (91.4° F.) by noninvasive treatment has beendemonstrated to be surprisingly effective in recent clinical studies.The use of cold gel and ice packs produced cooling of approximately 0.9°C. (1.6° F.) per hour, and resulted in a nearly 100 percent improvementin neurologically intact survival (Bernard S. A. et al., Treatment ofComatose Survivors of Out-of-Hospital Cardiac Arrest with InducedHypothermia, 346 NEW ENG. J. MED. 557-563 (2002)). In another study,cold air was found to be capable of cooling patients at a rate of about0.25° C. (0.45° F.) per hour, which caused a 40 percent improvement inthe same endpoint (Sterz F. et al., Mild Therapeutic Hypothermia toImprove the Neurologic Outcome after Cardiac Arrest, 346 NEW ENG. J.MED. 549-556 (2002)). In yet another study, a combination ofwater-filled cooling blankets and ice packs applied to the skin resultedin a cooling rate of 0.8° C. (1.4° F.) per hour (Felberg et al.,Hypothermia After Cardiac Arrest—Feasibility and Safety of an ExternalCooling Protocol, 104 CIRCULATION 1799-1804 (2001)). Despite the successof these studies, increasing the rate of cooling may produce a higherrate of patient salvage.

Based on the current cooling procedures and systems, the presentinvention explores a unique solution to the problem of accelerated bodycooling. Namely, the present invention is based upon the hypothesis thatfull body contact with a liquid medium, such as cold water, would inducehigh rates of heat transfer. Beyond immersion, controlling the liquidtemperature and flow rate may allow further control of the coolingprocess, thereby producing a valuable system.

SUMMARY OF THE INVENTION

Among the several objects and features of the present invention may benoted the provision of an apparatus and method capable of decreasing thetime required to induce hypothermia in a patient; the provision of anapparatus and method capable of controlled warming of a patient; theprovision of such an apparatus and method that permits the delivery ofCPR during cooling or warming; the provision of such an apparatus andmethod in which cooling liquid is brought into direct contact with skin;the provision of such an apparatus and method that allows for cooling orwarming of the patient in a remote environment without electricity; andthe provision of such an apparatus that allows for cooling or warmingwhile the patient is in transport.

Generally, apparatus for adjusting the body temperature of a patientcomprises an enclosure defining an interior space for receiving at leasta portion of a patient's body therein. The enclosure is adapted forsubstantially sealingly enclosing the portion of the patient's bodywithin the interior space. The enclosure has an inlet for receiving heattransfer liquid into the interior space for flow over the patient's bodyin direct liquid contact therewith to promote heat transfer between thepatient's body and the heat transfer liquid. An outlet is in fluidcommunication with the interior space of the enclosure for exhaustingthe heat transfer liquid from the enclosure.

In another aspect of the present invention, an apparatus for adjustingthe body temperature of a patient comprises an enclosure as set forthabove adapted for enclosing the portion of the patient's body within theinterior space with the enclosure generally contiguous with at leastopposite sides of the portion of the patient's body. The enclosurefurther has an inlet and an outlet generally as set forth above.

In yet another aspect of the present invention, a method for controllingthe body temperature of a patient comprises the step of substantiallysealingly enclosing at least a portion of the patient's body within theinterior space of an enclosure with the enclosure being generallycontiguous with the portion of the patient's body. The method alsorequires directing a heat transfer liquid to flow within the interiorspace in direct liquid contact with the patient's body to promote heattransfer between the heat transfer liquid and the patient's body.

In still another aspect of the present invention, a method forcontrolling the body temperature of a patient comprises the steps ofenclosing at least a portion of the patient's body within the interiorspace of an enclosure with at least opposite sides of the portion of thepatient's body and directing a heat transfer liquid to flow generally asset forth above.

Other objects and features will be in part apparent and in part pointedout hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic of apparatus of the present invention for alteringthe body temperature of a patient;

FIG. 2 is a partial elevation of the apparatus of FIG. 1 with portionsof the enclosure removed to show detail;

FIG. 3 is an enlarged fragmentary section of the enclosure of FIG. 2;

FIG. 4 is a fragmentary elevation of the apparatus with a sealableopening formed by a pivotable flap;

FIG. 5 is a fragmentary elevation of the apparatus with a sealableopening sealed about an arm of the patient;

FIG. 6 is a fragmentary elevation of the apparatus with the arm of thepatient passing between an upper member and lower member;

FIG. 7 is a fragmentary elevation of the apparatus of FIG. 6 with theupper and lower members sealed together about the patient's arm;

FIG. 8 is a schematic of a portable control unit of the apparatus of thepresent invention;

FIG. 9 is a bottom view of the upper member of the apparatus showingliquid passages formed in the apparatus;

FIG. 10 is an enlarged fragmentary view of the upper member of FIG. 9;

FIG. 11 is a fragmentary side section of the upper member of FIG. 9;

FIG. 12 is a bottom view of a second embodiment of an upper member ofthe apparatus shown as having liquid passages formed therein;

FIG. 13 is a fragmentary section of an apparatus having a jacket with arigidifiable layer;

FIG. 14 is a fragmentary section of a second embodiment of apparatus ofthe present invention having a jacket with a rigidifiable layer;

FIG. 15 is a top plan view of a third embodiment of apparatus of thepresent invention;

FIG. 16 is an enlarged fragmentary elevation of the enclosure of FIG. 2;

FIG. 17 is a graph depicting the skin temperature and internal bodytemperature of a swine undergoing the method of the present invention;and

FIG. 18 is a graph of the internal body temperature of a swine subjectedto different methods of cooling.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

DETAILED DESCRIPTION OF THE. PREFERRED EMBODIMENT

Referring now to the drawings and particularly to FIG. 1, referencenumber 21 generally indicates an apparatus for adjusting the bodytemperature of a patient. The apparatus 21 generally comprises anenclosure 25 defining an interior space 27 for receiving at least aportion 31 of a patient's body therein. The enclosure 25 is configuredfor substantially sealingly enclosing the portion 31 of the patient'sbody (illustrated in FIG. 1 as all of the patient's body below the head)within the interior space 27 with the enclosure generally contiguouswith the patient's body. An inlet 35 of the enclosure 25 is adapted toreceive heat transfer liquid 39, such as water, saline or otherbiocompatible liquids, into the enclosure. The inlet 35 is further influid communication with the interior space 27 of the enclosure 25 todirect heat transfer fluid 39 into the interior space 27 for flowingover the patient's body portion 31 in direct contact therewith topromote heat transfer between the patient's body portion and the heattransfer liquid. The enclosure 25 also has an outlet 45 in fluidcommunication with the interior space 27 of the enclosure for exhaustingthe heat transfer liquid 39 from the enclosure. More particularly, theenclosure 25 is adapted to generally conform to the portion of thepatient's body 31 disposed within the interior space 27. Additionally,the inlet 35 and outlet 45 are positioned on the enclosure such thatupon enclosure of the patient's body portion 31 within the interiorspace 27, the inlet faces a side of the patient's body portion oppositethe outlet. Although any portion of the patient's body may be placedinside the enclosure 25, preferably the portion enclosed includes thebody of the patient from the neck 51 of the patient downward, includingthe torso 53, arms 57 and legs 61 of the patient.

In one embodiment, shown in FIG. 2, the enclosure 25 comprises a firstsheet member 71 and a second sheet member 75 in sealing engagement withone another generally at their respective edge margins to form theinterior space 27 for receiving the body portion 31. Here, the inlet 35extends through the first sheet member 71 and the outlet 45 extendsthrough the second sheet member 75. The sheet members 71,75 are disposedrespectively above and below the body portion 31 of the patient, therebyarranging the inlet 35 and the outlet 45 on opposite sides of thepatient. As shown in FIG. 2, the inlet 35 and outlet 45 may comprisemultiple sub-inlets 35′ and sub-outlets 45′. These sub-inlets andsub-outlets facilitate the flow of heat transfer liquid 39 over a largerarea of the enclosed portion 31 of the patient's body, thereby promotingincreased contact between the liquid and the portion of the patient'sbody.

More specifically, the first sheet member 71 may comprise a lower member77 for placement beneath the body portion 31 and the second sheet member75 may comprise an upper member 79 for placement above the body portion.The enclosure 25 of FIG. 2 depicts such a configuration, and is shownfor illustrative purposes only. It is contemplated, for instance, thatthe outlet 45 may extend through the first sheet member 71, or lowermember 77, while the inlet 35 may extend through the second sheet member75, or upper member 79 (not shown). In the configuration depicted inFIG. 2, where the inlet 35 lies below the outlet 45, air trapped withinthe interior space 27 of the enclosure 25 will move up toward the outletand be purged from the enclosure via the outlet. Purging air from theenclosure 25 increases the liquid contact with the body portion 31,thereby promoting more heat transfer between the body portion and liquid39 for better control of body temperature. The first sheet member 71 andthe second sheet member 75 of the illustrated embodiment additionallycooperate to form at least one neck opening 81 in the enclosure 25 (FIG.2). The neck opening 81 is preferably sized and shaped for sealingengagement of the sheet members 71,75 with the neck 51 of the patient atthe opening. The enclosure 25 may include a strap, a hook and loopfastener or other sealing device (not shown) at the neck opening 81 tofurther promote sealing of the neck opening about the neck 51 of thepatient at the opening. Adhesive hydrogels may also be applied to theneck 51 of the patient to further encourage sealing of the enclosure 25about the patient's neck.

The first sheet member 71 includes a first sealing portion, generallyindicated at 83, and the second sheet member 75 includes a secondsealing portion, generally indicated at 87 (FIG. 3). The sealingportions 83,87 are sealingly engageable with one another for sealing theinterior space 27 of the enclosure 25. The first and second sealingportions 83,87 each further comprise a gasket 95, for sealing the firstand second sheet members 71,75, and a hook and loop fastener, generallyindicated 97, for holding the sheet members in sealed engagement. Thegasket 95 preferably includes a first bead 95 a on the first sealingportion 83 and a second bead 95 b on the second sealing portion 87. Suchbeads 95 a, 95 b may be formed from an elastomeric material, such asrubber. A hook and loop fastener, generally indicated 97, is preferablypositioned on opposite lateral sides of the beads 95 a, 95 b, such thatthe hook and loop fastener portions compress the beads, forming a sealedenclosure 25. This seal inhibits liquid 39 leakage from the enclosure25, or a loss of vacuum within the interior space 27 of the enclosure.

Referring now to FIGS. 4-7, the enclosure 25 further includes a sealableopening 101 for accessing the interior space 27 of the enclosure. Such asealable opening 101 may be used for accessing the patient during use ofthe apparatus 21. The sealable opening 101 may also be sealed about anobject, such as medical tubing 105, cords or other items which need topass through the enclosure 25 into the interior space thereof. In oneconfiguration, depicted in FIG. 4, a pivotable flap 109 defines aclosure for the sealable opening 101. Medical tubing 105 or other itemsmay pass through the opening 101 with the flap 109 sealed about them.Moreover, as shown in FIG. 5, the sealable opening 101 may be securedabout a second body portion 113 of the patient's body, such as an arm 57or leg, thereby allowing the second body portion to extend exterior ofthe enclosure 25 while substantially sealingly enclosing the bodyportion 31. This is particularly important where access to the secondbody portion 113 of the patient for performing a medical procedure, suchas drawing blood or placing a medical device, e.g., an intravenouscatheter, is warranted. As shown in FIGS. 6 and 7, the second bodyportion 113 may also extend out from the enclosure between the lowermember 77 and upper member 79, e.g., without the use of an additionalopening 101. In this configuration, the first and second sealingportions 83,87 cooperate to form a seal about the second body portion113 as it extends out from the enclosure 25, as shown in FIG. 7. In eachof these configurations, adhesive hydrogels may be applied to the secondbody portion 113 of the patient to further promote sealing of theenclosure 25 about the second body portion.

Referring now to FIG. 8, the apparatus 21 further comprises a portablecontrol unit, generally indicated at 117, for controlling operation ofthe apparatus. The control unit 117 comprises a liquid delivery system121 for directing the heat transfer liquid 39 to flow through the inlet35 of the enclosure 25 into the interior space 27 to the outlet 45 ofthe enclosure. The liquid delivery system 121 comprises a pump apparatus125, a valve apparatus 127, a heat exchanger 129 and a temperaturesensor 131. The liquid delivery system 121 is a generally closed,continuous flow system whereby liquid 39 exhausted from the outlet 45 isdirected to flow back to the inlet 35 for flow into the interior space27 of the enclosure 25. A control system 135 communicates with theliquid delivery system 121 to control the flow of liquid 39 through theenclosure 25. The temperature sensor 131 is adapted for sending a bodytemperature reading of the patient to the control system 135, so thatthe control system can use this information to control the pumpapparatus 125, valve apparatus 127 and heat exchanger 129. The controlsystem 135 comprises a programmable controller 141, an H-bridge drivecircuit 143, a voltage limiter 145 and pump drivers 147. The controlsystem 135 provides temperature regulation, drives the pump apparatus125 and controls the valve apparatus 127. The apparatus 21 furtherincludes a user interface 151 for communicating the status of the systemto the user. The user interface 151 includes a display 153 for visuallyindicating particular parameters of the system and controls 155 thatallow the user of the system to selectively control particular systemfunctions. For example, such controls may allow the user to input aset-point, or target, body temperature for the patient. The display 153,for example, could display this set-point temperature along with theactual body temperature of the patient, the liquid 39 temperature andthe liquid flowrate, among other things.

Referring back to FIG. 1, the portable control unit 117 comprises anoutlet pump 161 in fluid communication with the outlet 45 for exhaustingheat transfer liquid 39 from the enclosure 25 and an inlet pump 163 influid communication with the inlet 35 for pumping heat transfer liquidinto the enclosure. The heat exchanger 129 is in fluid communicationwith the outlet pump 161 and the inlet pump 163, such that liquid 39exhausted from the enclosure 25 by the outlet pump passes through theheat exchanger before entering the inlet pump. For example, the pumps161,163 may be 12 volt direct current pumps having a pumping capacity of2.4 liters per minute (0.63 gallons per minute). The pumping capacity ofsuch pumps may be increased to 3.0 liters per minute (0.79 gallons perminute) with 18 volts, but not without degrading pump life. Shouldhigher flowrates or other parameters be required, alternative pumps,such as higher capacity gear or centrifugal pumps, may be used withoutdeparting from the scope of the present invention.

The pump apparatus 125 further comprises a reservoir 167 in fluidcommunication with the inlet pump 163 and the heat exchanger 129, suchthat liquid 39 passing through the heat exchanger flows into thereservoir before flowing into the inlet pump. The relative positions ofthe reservoir 167 and heat exchanger 129 may also be reversed, such thatliquid 39 from the enclosure 25 flows directly into the reservoir forstorage, until passing from the reservoir and through the heat exchangerimmediately before reentering the enclosure. Such an arrangement mightbe useful if rapid changes in the liquid 39 temperature were required.Returning now to the original configuration, the reservoir 167 collectsliquid 39 at the temperature induced by the heat exchanger 129 andstores it before the inlet pump 163 pumps the liquid into the enclosure25. The reservoir 167 may be insulated (not shown) to help maintain thetemperature of the heat transfer liquid 39 before it is pumped into theenclosure 25. Although any size reservoir may be used, a reservoirhaving a capacity of about 12 liters (3.2 gallons) is preferable. Evenmore preferable is a reservoir having a smaller volume, such as 4 liters(1.1 gallons), where such a volume of fluid in the reservoir issufficient to ensure continued cycling of liquid through the apparatus21. The reservoir 167 may also comprise a liquid temperature changecomponent 169 in heat transfer communication with the liquid 39 forchanging the temperature of the liquid. The component 169 may alsoprovide temperature stabilization once the liquid 39 within thereservoir 167 reaches a particular temperature. In one configuration,the liquid temperature change component 169 contacts the liquid 39within the reservoir 167. The component 169 may be any material capableof absorbing or releasing heat, such as ice or another phase changematerial.

The pump apparatus 125 further comprises a bypass conduit 173 in fluidcommunication with the heat exchanger 129 and the inlet pump 163. Thebypass conduit 173 communicates at one end with a first three-way valve177, between the outlet pump 161 and the heat exchanger 129, and at itsother end with a second three-way valve 179, between the inlet pump 163and the enclosure 25. While operating in a normal mode, without use ofthe bypass conduit 173, the liquid 39 passes through the outlet pump161, the first three-way valve 177, the heat exchanger 129, thereservoir 167, the inlet pump 163, the second three-way valve 179 andthe enclosure 25. The normal mode is used when a patient is enclosedwithin the enclosure 25 and liquid 39 is being passed over the bodyportion 31. In bypass mode, as directed by the user with the controls155 of the user interface 151 (FIG. 8), the position of the first andsecond three-way valves 177,179 switch to divert flow of the liquid 39from the enclosure 25 to the bypass conduit 173. In addition, the outletpump 161 is turned off during bypass mode, since liquid bypasses theoutlet pump. As a result, liquid 39 flows through the first three-wayvalve 177, the heat exchanger 129, the reservoir 167, the inlet pump163, the second three-way valve 179 and the bypass line 173. Bypass modeallows the pump apparatus 125 to control the temperature of the liquid39, without passing the liquid through the enclosure 25. The bypass modeis particularly useful for pre-cooling or pre-heating the liquid 39within the reservoir 167. This allows the apparatus 21 to prepare theliquid for use before the patient is placed within the enclosure 25.

In operation, the functioning of the liquid delivery system 121 cancontrol the pressure within the interior space 27 of the enclosure bycontrolling the movement of liquid 39 through the enclosure 25. Forexample, where the flowrate of the outlet pump 161 is greater than theflowrate of the inlet pump 163, the flowrate difference will create anegative gage pressure, or vacuum, within the interior space 27 of theenclosure 25. Furthermore, a lower pressure within the interior space 27of the enclosure 25, relative to the exterior of the enclosure, isbeneficial in that it (i) draws the enclosure against the body of thepatient to maintain the liquid close to the patient's skin, (ii)minimizes leakage of the enclosure, (iii) encourages blood flow to theskin surface, (iv) minimizes the amount of liquid needed to fill theenclosure and (v) allows the patient's body to be manually compressed ordecompressed. Decompression may be readily facilitated by the additionof a hook and loop fastener on the outside of the enclosure 25 (notshown), to which medical personnel could attach a mating decompressiontool. The vacuum may be further enhanced by directing the flow of liquid39 into the bottom of the enclosure 25 and out the top. By requiring thepump to raise the liquid 39 as it passes through the enclosure 25, thepressure drop across the enclosure will increase as flowrates remainconstant. Preferably, a vacuum within the enclosure 25 creates a gagepressure within the interior space 27 of between about 0 kiloPascal (0pounds per square inch) and about −14 kiloPascals (−2.0 pounds persquare inch). Alternately, positive gage pressure may be maintainedwithin the enclosure 25, as discussed later herein.

The heat transfer liquid 39 preferably has a temperature less than thetemperature of the body portion 31 of the patient so that the liquidcools the body portion of the patient. Preferably, the heat transferliquid 39 has a temperature in a range of about 1° C. (34° F.) to about2° C. (36° F.). Such a temperature range provides adequate cooling whileminimizing any adverse affects to the skin of the patient. Heat transferliquid 39 introduced into the enclosure 25 at such a temperature hasbeen found to cool the body at a sufficient rate to induce hypothermia.Examples of hypothermia inducement in animal subjects are described ingreater detail below.

Alternately, the enclosure 25 may be used to warm the body portion 31 ofthe patient within the enclosure if the heat transfer liquid 39 has atemperature greater than the temperature of the portion of the patient'sbody. One application of such a warming enclosure 25 would be to warm apatient suffering from unintended hypothermia. Preferably, the heattransfer liquid has a temperature in a range of about 43° C. (109° F.)to about 47° C. (117° F.), or more preferably about 45° C. (113° F.).

As described briefly above, the apparatus 21 of the present inventioncomprises a heat exchanger 129 in fluid communication with the liquiddelivery system 121 for altering the temperature of the liquid 39 froman outlet temperature T_(o), measured after the liquid exits theenclosure 25, to an inlet temperature T_(i), measured before the liquidenters the enclosure (FIG. 1). After passing through the heat exchanger129, the liquid 39 may be reintroduced into the enclosure 25 asdescribed above. This allows the same liquid 39 to be used repeatedlybetween the enclosure 25 and the liquid delivery system 121. Varioustypes of heat exchangers 129 are contemplated as being within the scopeof the present invention. For instance, the heat exchanger 129 of thepresent invention may incorporate a Peltier device or a phase-changematerial to facilitate returning the liquid 39 to its inlet temperatureafter passing through the enclosure 25 and being altered by thetemperature of the body portion 31 of the patient. Such a heat exchanger129 requires a flowrate of at least 1.5 liters per minute (0.40 gallonsper minute) to maintain adequate efficiency.

In another embodiment, depicted in FIGS. 9-11, the enclosure 25comprises a sheet-like body-facing component 183 and a sheet-like outercomponent 185 that are adapted for face-to-face engagement with oneanother. The components 183,185 are joined to one another along theirfacing sides to form at least one liquid passage 189 between thecomponents. The liquid passage 189 is preferably shaped and sized forfluid communication with the inlet 35 for receiving the heat transferliquid 39. The body-facing component 183 further has at least one, andpreferably several, openings 193 therein corresponding to the liquidpassage 189 for allowing the liquid 39 to pass from the liquid passageto between the body-facing component 183 and the portion of thepatient's body 31. Before the liquid passage 189 fills with heattransfer liquid 39, the sheet-like body-facing component 183 andsheet-like outer component 185 of the passage lie flat against oneanother. Once liquid 39 flows inside the passage 189, thecross-sectional area of the passage increases to allow liquid to flowbetween the components 183,185. To seal the components together to formthe liquid passage 189, heat sealing is preferably used because itprovides adequate strength without requiring additional raw materials.Other methods of sealing the components 183,185 to one another, such asadhesives, are also contemplated as being within the scope of thepresent invention.

The liquid passage 189 of the present configuration may be furtherconfigured to distribute liquid 39 over a larger surface area of thepatient's body. For example, the liquid passage 189 may comprise atleast one main liquid passage 197 extending longitudinally of theenclosure 25, and at least two secondary liquid passages 199 extendinglaterally out from the main liquid passage. Preferably, the main liquidpassage 197 branches into many secondary liquid passages 199 to furtherdistribute liquid 39 to the patient's body portion 31 within theenclosure 25. The path of these passages may vary without departing fromthe scope of the present invention.

The components 183,185 may be joined further along their opposed sides183′,185′ to form gas pockets 203. Such pockets 203 are preferably atleast partially filled with gas 205 (e.g., air) such that the pocketsact as cushions to engage the body portion 31, holding an adjacentportion of the body-facing component 183 slightly away from the bodyportion of the patient to increase the interior space 27. As the pockets203 lift and hold the body-facing component 183 away from the patient'sbody portion 31, they facilitate liquid 39 movement between thebody-facing component and the portion of the patient's body. Because thepockets 203 are rounded, their contact area with the patient's bodyportion 31 is limited, so that more liquid 39 can contact the skin,thereby increasing the heat transfer effect of the liquid. Where theliquid passages 189 extend abundantly throughout the enclosure 25, airpockets 203 may not be necessary for holding the body-facing component183 slightly away from the patient's body.

Where the torso 53, arms 57 and legs 61 of the patient are within theinterior space 27 of the enclosure 25 (e.g., FIG. 1), the main liquidpassages 197 are preferably arranged to engage the patient's torso at aposition offset from the medial (e.g., longitudinal center) line of thepatient's body, as shown in FIG. 12. This feature is particularly usefulwhere CPR is to be administered to the patient, because chestcompressions occur generally along the medial line of the patient. Wherethe patient is placed within the enclosure 25 and the main liquidpassage 197 corresponds approximately with the medial line of thepatient, chest compressions may systematically block the flow of liquid39 through the main liquid passage, thereby reducing liquid flow throughthe enclosure 25. Where the main liquid passages 197 are offset from themedial line of the patient as shown in FIG. 12, chest compressionsperformed in rendering CPR treatment are less disruptive of liquid 39flow through the enclosure 25. Although not shown in FIG. 12, gaspockets 203, as disclosed previously, may be incorporated into thepresent configuration. Other passage arrangements are also contemplatedas being within the scope of the present invention.

A further embodiment of the present invention includes a portablecontrol unit 117 comprising the liquid delivery system 121, a userinterface 151, a power source 211 and the control system 135 forpowering and controlling the liquid delivery system (FIG. 8). Such aportable control unit 117 would be particularly useful where theapparatus 21 is to be used at a remote site, where electricity isunavailable. Moreover, the self-contained nature of the portable controlunit 117 allows it to be carried to the patient, administered to thepatient and remain operational while the patient is transported to amedical facility. In one preferred embodiment, the power source 211 is abattery. Other portable power sources, such as engine-based generatorsand motorized vehicles (e.g., electrical power derived from either) arealso contemplated as potential sources of power. In order for thecontrol system 135 to properly control the flow of liquid 39 through theenclosure 25 to control the body temperature of the patient, thetemperature sensors 131 of the portable control unit engage thepatient's body 31 via wires 133 to monitor the temperature of thepatient. Inputs from these temperature sensors 131 feed into the controlsystem 135 for monitoring and controlling the temperature of thepatient.

In another embodiment, controlling the liquid delivery system 121 cancontrol the fluid pressure within the enclosure by controlling the flowof liquid 39 through the enclosure 25. For instance, where the flowrategenerated by the outlet pump 161 is less than the flowrate generated bythe inlet pump 163, the flowrate differential will create a positivegage pressure, e.g., greater than atmospheric pressure, within theinterior space 27 of the enclosure 25. Pressurizing the interior space27 generally applies a compressive force to the patient's body portion31 as the heat transfer liquid 39 flows over the patient. Preferably,the positive gage pressure within the interior space 27 of between about0 kiloPascals (0 pounds per square inch) and about 28 kiloPascals (4pounds per square inch).

However, without restraining the size of the enclosure 25, a positivegage pressure within the interior space 27 would tend to expand theenclosure as more liquid 39 enters the unrestrained enclosure. Thus,several embodiments are contemplated for limiting such outward expansionof the enclosure 25 under positive internal pressure. For example, atleast one strap 215 may surround the exterior of the enclosure 25 toinhibit or otherwise limit outward expansion of the enclosure andexerting pressure upon the body portion 31 within the enclosure (e.g.,FIG. 8). The strap 215 may further be selectively positionable forengagement with particular portions of the enclosure 25 in contact withparticular portions of the patient's body 31 to apply pressure in aparticular area. This feature may be particularly useful where thepatient is bleeding and pressure upon a specific area may inhibitfurther bleeding.

Referring now to FIGS. 13 and 14, expansion of the enclosure 25 may alsobe limited by a jacket 221 surrounding the enclosure. The jacket 221 isless elastic than the enclosure 25 and adapted to resist expansion ofthe enclosure upon pressurizing the interior space 27. The jacket 221 isformed from a material resistant to expansion to thereby generallymaintain the shape of the pressurized enclosure 25. For example, asuitable jacket 221 may be constructed from a rigid plastic such aspolycarbonate, Acrylonitrile Butadiene Styrene (ABS) or acrylic. Thisjacket 221 may incorporate reinforcing fibers made of a high tensilestrength material such as KEVLAR®, a federally registered mark of E. I.du Pont de Nemours and Company of Wilmington, Del., U.S.A., graphite orglass. Alternately, the jacket 221 may comprise an outer member 225 anda rigidifiable layer 227 between the outer member and the enclosure 25.The rigidifiable layer 227 need not be completely rigid, but ispreferably less elastic than the enclosure 25 to limit expansion of theenclosure upon pressurizing the interior space 27. In one configuration,the rigidifiable layer 227 comprises small particulate matter 231, suchthat the rigidifiable layer may be placed in fluid communication with avacuum source 235 for removing gas (e.g., air) from between theindividual particles of particulate matter, thereby rigidifying therigidifiable layer between the jacket 221 and enclosure 25 by compactingand densifying the particles with respect to one another (FIG. 13). Oncethe rigidifiable layer 227 is rigidified, a positive gage pressure maybe maintained within the enclosure 25, while limiting further expansionof the enclosure. One suitable particulate matter 231 is polystyrenebeads, for example. The rigidifiable layer 227 is shown in FIG. 13without particulate matter 231 throughout the layer to simplify thefigure, although the rigidifiable layer is preferably fully filled withsuch matter in actual use. Instead of particulate matter, therigidifiable layer 227 may comprise a polymer capable of starting as anon-solid and solidifying due to a chemical reaction (FIG. 14). Forexample, a polymer such as two-component, foam-in-place polyurethane maybe used to rigidify the rigidifiable layer 227.

With reference to FIG. 15, the apparatus 21 further comprises a headcooling device, generally indicated at 241, engaging the head 243 of thepatient for circulating the heat transfer liquid 39 in contact with thehead of the patient (FIGS. 1 and 2). The head cooling device 241 furthercomprises an inlet 247, providing a path for entry of liquid 39 fordirectly contacting the head 243, and an outlet 249, providing a pathfor exhausting liquid from the head cooling device. In one embodiment,the head cooling device 241 comprises a helmet 253 for placement uponthe head 243 of the patient (FIGS. 1 and 2). The helmet 253 is adaptedfor sealing engagement with the head 243 of the patient. The helmet 253is shaped such that the interaction of the helmet and the head 243 forma void 257 so that the heat transfer liquid 39 may flow through the voidand contact the head to alter the temperature of the head. In anotherconfiguration, the head cooling device 241 comprises a hood 263 attachedto the enclosure 25 and wrapping about the head 243 of the patient (FIG.15). The hood 263 also cooperates with the head 243 to form a void 257between the hood and the head, thereby allowing the heat transfer liquid39 to contact the patient's head.

In addition to the head cooling device 241, a mask 267 is adapted forplacement over the face of the patient to deliver air to the mouth ornose of the patient via tubing 269 (FIG. 1). The mask 267 may deliverambient air or oxygen to the patient, as would a conventional breathingmask, or the air delivered through the mask may be at a temperaturedifferent than the temperature of the patient's body to aid in coolingor warming the patient.

Additionally, at least a portion of the upper member 79, and preferablythe entire upper member, may be transparent for viewing the body portion31 within the enclosure 25. For instance, a sheet-like body-facingcomponent and sheet-like outer component (as described above) may beformed from a transparent material, such as PVC (polyvinyl chloride),polyethylene or polyurethane.

Referring now to FIGS. 9 and 15, the enclosure 25 may further comprisehandles 271 for lifting the enclosure with the body portion 31 receivedwithin the enclosure. Such handles 271 may be attachable to theenclosure 25 or formed integrally with the enclosure. For instance,handles 271 may be formed integrally with the lower member, as shown inFIG. 9. Handles 271 provide ease of movement of the enclosure 25,allowing the patient and enclosure to be easily lifted and moved toanother location, while heat transfer liquid 39 continues to flowthrough the enclosure for altering the temperature of the patient.

In another embodiment, depicted in FIG. 15, the upper member 79 ishinged to the lower member 77 along an edge 279 of the upper member.This ensures that the upper member 79 and lower member 77 remainattached and properly aligned for use with respect to one another. Inthis configuration, the upper member 79 is slightly smaller than thelower member 77. This allows the sealing portions 83,87 of the enclosure25 to lie laterally inward from the peripheral edge of the lower member77 of the enclosure.

Referring now to FIG. 16, the enclosure 25 of the present inventionpreferably comprises a liquid impermeable outer layer 285, a meshbody-facing layer 289 and a layer of batting 293 between the outer layerand the body-facing layer. The liquid impermeable outer layer 285retains the heat transfer liquid 39 within the enclosure 25, while theporous batting layer 293 allows liquid to pass from the batting intocontact with the patient's body portion 31 for flow across the skinthroughout the enclosure. The mesh layer 289 holds the batting layer 293in place, allowing substantial contact between the body portion 31 andthe liquid 39 within the batting. In one configuration, the liquidimpermeable outer layer 285 further comprises a neoprene outer shell 295with an inner layer 297 of aluminum laminated polyester. The outer shell295 of neoprene repels liquid, while the inner layer 297 helps insulatethe enclosure 25. Preferably, outer shell 295 comprises about 3.2 mm(0.125 inch) to about 1.6 mm (0.0625 inch) thick Neoprene, which iscommercially available from John R. Sweet Co. of Mustoe, Va., USA. Theinner layer 297 preferably comprises Aluminum Laminated Polyethylene,which is commercially available from Wal-Mart Stores, Inc. ofBentonville, Ark., USA. The middle layer of batting 293 preferablycomprises polyester batting, and the mesh layer 289 comprises a nylonscreen. For example, the layer of batting 293 may be low loft polyesterbatting, such as is available from Carpenter Co. of Taylor, Tex., USA.The mesh layer 289 preferably is a Nylon screen mesh, such as isavailable from McMaster-Carr Supply Company of New Brunswick, N.J., USA.Because each of these components is relatively thin, the enclosure 25may be folded or rolled into a compact shape for ease of storage. Thetotal thickness of each member 77,79 of the enclosure is preferably lessthan about 5 mm (0.2 inch).

In one embodiment of a method of the present invention for controllingthe body temperature of a patient, at least a portion 31 of thepatient's body is substantially sealingly enclosed within the interiorspace 27 of an enclosure 25. The enclosure 25 is generally contiguouswith the portion 31 of the patient's body. The method further comprisesdirecting a heat transfer liquid 39 to flow within the interior space 27in direct liquid contact with the patient's body to promote heattransfer between the heat transfer liquid and the patient's body.Specifically, the method comprises directing the heat transfer liquid 39to flow from an inlet 35 of the enclosure 25 through the interior space27 of the enclosure to an outlet 45 thereof. The method may furthercomprise maintaining heat transfer liquid 39 in contact with thepatient's body within the interior space 27 between the enclosure inlet35 and the enclosure outlet 45. Such a method may also comprisepositioning the patient's body generally within the interior space 27between the enclosure inlet 35 and the enclosure outlet 45, such thatthe enclosure inlet and enclosure outlet are disposed on generallyopposite sides of the patient's body. In addition, the step of directingheat transfer liquid 39 to flow through the interior space 27 of theenclosure 25 may comprise generating a vacuum within the interior spaceof the enclosure. The method may further comprise the step of applying acompressive force to the patient's body as heat transfer liquid 39 isdirected to flow through the interior space 27 of the enclosure 25.

The method may further comprise the step of performing CPR upon thepatient simultaneous with the directing step described above. With priorsystems for cooling or heating the patient's body, cooling and heatinghad to be temporarily stopped during resuscitation. With the method ofthe present invention, CPR does not interfere with the heating orcooling of the patient.

In still another embodiment, a method for controlling the bodytemperature of a patient comprises the steps of enclosing at least aportion of the patient's body within the interior space 27 of anenclosure 25 with the enclosure being generally contiguous with at leastopposite sides of the portion 31 of the patient's body. The methodfurther comprises directing a heat transfer liquid 39 to flow within theinterior space 27 in direct liquid contact with at least the oppositesides of the portion of the patient's body to promote heat transferbetween the heat transfer liquid and the patient's body.

To examine the process of induced hypothermia in a quantifiable manner,a series of preliminary experiments were conducted using an acute animalpreparation. A description of such experiments follows.

EXAMPLE 1 Swine Packed in Ice

The first example studied the effect of total encasement of an animal,here a swine, in ice. This study was conducted in view of recentclinical reports suggesting that cooling gel packs work reasonably well.The study was done by placement of approximately 45 kg (100 pounds) ofice in 2.3 kg (5 pound) plastic bags both under and around the swine.Swine body temperatures and vital signs were then monitored over time,and the ice was removed when the observed core body temperature haddropped from about 34.5° C. (94.1° F.) to about 28.8° C. (83.8° F.).

More specifically, a first swine having a mass of 36 kg (79 pounds) wasanaesthetized with Telazol®, a federally registered mark of A.H. RobinsCo. of Richmond, Va., U.S.A., and zylazine. The hair of the swine wasalso clipped. The swine was then instrumented with an electrocardiogram(ECG) via conventional pads for electrically monitoring its heart rhythmduring the experiment and a respirator for maintaining properventilation. A pulmonary artery catheter was placed via the jugular veinfor monitoring the pulmonary artery pressure and blood temperaturewithin the artery. Catheter placement was confirmed by visualizing rightventricular and subsequently pulmonary artery pressure while advancingthe catheter. A thermistor sensor of the catheter was connected to atemperature monitor and calibrated in advance, which was then used tocalibrate two other type T thermocouples. The first type T thermocouplewas connected to the swine's skin under the right front leg withadhesive tape. The second thermocouple was placed deep within theuppermost ear of the swine and then sealed with foam insulation. Allsensors were connected to a DATAQ A/D converter system (available fromDATAQ Instruments, Inc. of Akron, Ohio, USA) and digitized during theexperiments at a rate of 120 Hertz. Once anaesthetized and lying on itsside, the exposed exterior of the swine was packed with conventional 2.3kilogram (5 pound) bags of ice. Approximately 20 bags were used in theexperiment, such that a bag of ice was contacting the majority of theskin of the swine.

The skin temperature and pulmonary artery blood temperature were thenrecorded over time to determine the cooling rate of the swine due tobeing packed in ice. The temperature results of this example aredepicted in FIG. 17 as curves 301 and 303. For FIGS. 17 and 18, thevertical axis of the chart indicates temperature in Celsius, while thehorizontal axis indicates time in minutes. The maximum and minimumvalues shown on the temperature scales vary between figures. Curve 301indicates the pulmonary artery temperature of the swine and curve 303represents the skin temperature. As would be expected, the skintemperature of the swine leads the pulmonary artery temperature, as theskin is providing the cooling for the entire body. Curve 301demonstrates that eight minutes into the cooling process, the core bodytemperature of the swine dropped by 1° C. (1.8° F.). After eleven,seventeen and twenty-five minutes, the core temperature had dropped by atotal of 2° C. (3.6° F.), 3° C. (5.4 F°) and 4° C. (7.2° F.),respectively.

EXAMPLE 2 Swine in Enclosure with Liquid Flow

In the second example, a second swine was enclosed in a prototypeenclosure of apparatus of the present invention, generally as describedabove. The apparatus was used to cool and re-warm the animal severaltimes over a period of several hours. The enclosure was operated in oneof two ways, with water, as the heat transfer liquid, flowing from thetop to the bottom of the enclosure or with water flowing oppositely,bottom to top. Pumping water into the interior space at the top of theenclosure and then out of the interior space at the bottom generated apositive gage pressure within the interior space of the enclosure.Pumping water into the interior space at the bottom of the enclosure andthen out of the interior space at the top of the enclosure generated asub-atmospheric pressure, or partial vacuum, within the interior spaceof the enclosure. In this mode, the enclosure becomes more conformal tothe body and allows for a smaller amount of circulating water asdescribed above.

In this example, a second swine having a mass of 36 kg (79 pounds) wasanaesthetized, hairs clipped, instrumented and laid on its side similarto the first swine described above. The swine was then placed within anenclosure sized and shaped for a swine, but substantially as describedabove. The enclosure was designed to achieve direct liquid contact withthe swine's skin. The enclosure included a lower member placed beneaththe swine and an upper member placed over the swine. Only the snout ofthe swine extended out through an opening in the enclosure, allowing theswine to breathe. The lower member and upper member were joined aboutfirst and second sealing portions located generally at the edge marginof each member, generally as described above. The enclosure was sealedaround the snout of the swine so that a negative gage pressure could begenerated within the interior space of the enclosure. The upper andlower members each additionally included five sub-inlets and fivesub-outlets, respectively, for circulating water throughout the interiorspace of the enclosure. The enclosure was fabricated from layers ofneoprene, aluminized polyester, polyester batting and nylon mesh,generally as set forth above.

Cooling or warming water was then pumped by computer-controlled gearpumps from reservoirs located near the swine into the enclosure. Thepumps used were capable of moving 1.7 liters (0.45 gallon) per minute.As described above, the enclosure dispersed the liquid within theinterior space around, over and under the animal in direct contacttherewith. The heat exchange system of this example utilized an ice bathreservoir pumped through the enclosure for cooling. The ice bath keptthe inlet temperature of the water at about 1 to 2° C. (34 to 36° F.).For the re-warming portion of the experiment, hot water was applied tothe swine at an inlet temperature of 45° C. (113° F.).

The skin temperature and pulmonary artery blood temperature were thenboth recorded over time to determine the cooling rate of the swine. Thetemperature results of this experiment are depicted in FIG. 18 as curves305, 307 and 309. Curve 305 indicates the pulmonary artery temperatureof the swine packed in ice from example 1, curve 307 indicates thepulmonary artery temperature of the swine in the enclosure with watermoving from bottom to top and curve 309 indicates the pulmonary arterytemperature of the swine in the enclosure with water moving from top tobottom.

Reviewing curve 307, which pertains to bottom to top water flow, thecore body temperature of the swine as measured by the pulmonary arterycatheter dropped by 1° C. (1.8 F°) in the first four minutes of thecooling process. Such cooling is twice as fast as the swine packed inice. Moreover, after seven, ten and fourteen minutes, the swine's coretemperature had fallen by a total of 2° C. (3.6° F.), 3 C° (5.4° F.) and4° C. (7.2° F.), respectively. This method cooled the swine by 4° C.(7.2° F.) in fourteen minutes, which is 79% faster than the swine packedin ice. Similarly, the enclosure employing top to bottom flow, curve309, cooled the swine more quickly than example 1. At three, six, eightand twelve minutes after beginning the test, for example, the swine'score temperature had fallen by a total of 1° C. (1.8° F.), 2 C° (3.6°F.), 3° C. (5.4° F.) and 4° C. (7.2° F.), respectively. The top tobottom flow cooled the swine by 4° C. (7.2° F.) in twelve minutes, whichis 108% faster than the swine packed in ice.

Comparing this rate to published cooling rates from experiments usingcooled air, the cooling rates of the present example are much better.Comparing with the hypothermia research noted above (Sterz F. et al.,Mild Therapeutic Hypothermia to Improve the Neurologic Outcome afterCardiac Arrest, 346 NEW ENG. J. MED. 549-556 (2002)), where cooled airwas the medium selected for cooling body temperature, Sterz notes a 1°C. (1.8° F.), 2° C. (3.6° F.) and 3 C° (5.4° F.) core temperature dropin 4 hours, 6 hours and 10 hours, respectively, on human subjects.Obtaining such cooling rates in a swine in a matter of minutes,indicates much more rapid cooling, even recognizing body massdifferences between swines and humans.

The results of these examples are summarized in the following table:

Enclosure, Enclosure, Bottom to Top to Top Bottom Cooled Air CoolingPacked Cooling Cooling (Sterz) Method Ice [*] [*] [*] [**] 1 C. ° (1.8 8 minutes  4 minutes  3 minutes  4 hours F. °) drop in temperature 2 C.° (3.6 11 minutes  7 minutes  6 minutes  6 hours F. °) drop intemperature 3 C. ° (5.4 17 minutes 10 minutes  8 minutes 10 hours F. °)drop in temperature 4 C. ° (7.2 25 minutes 14 minutes 12 minutes — F. °)drop in temperature [*] 36 Kg Swine [**] Clinical subjects

To summarize, a 4° C. (7.2° F.) temperature drop can be achieved in a 36kg (79 pounds) animal with normal circulation in 12 minutes. This is asignificantly faster core temperature drop than that achieved by packingthe same size animal in ice or in clinical studies with human subjectsutilizing cooled air. While the animals of the examples had relativelynormal circulation, and were under anesthetic agents, the cooling ratesachieved are significant. Such therapeutic cooling has the potential tosignificantly increase the chances of neurologically intact survivalfollowing cardiac arrest. Such therapy may also be effective in thetreatment of stroke.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

When introducing elements of the present invention or the preferredembodiment(s) thereof, the articles “a”, “an”, “the” and “said” areintended to mean that there are one or more of the elements. The terms“comprising”, “including” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements.

As various changes could be made in the above without departing from thescope of the invention, it is intended that all matter contained in theabove description and shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

1. Apparatus for adjusting the body temperature of a patient in a supineposition, said apparatus comprising: an impermeable upper member forplacement above the patient's body; an impermeable lower member forplacement beneath the patient's body, said lower member being engageablewith said upper member to form an interior space for receiving a portionof a patient's body from the neck of the patient downward, including thetorso, arms, and legs of the patient; said upper member having a footend and a head end spaced longitudinally from the foot end fordisposition nearer to the patient's head than said foot end, and atleast one inlet being disposed on the upper member intermediate the footand head ends, the at least one inlet being disposed closer to said headend than said foot end, the inlet opening directly into said interiorspace and being configured for directing heat transfer liquid into saidinterior space to flow over the top of the patient's body towards theback of the patient's body so that said heat transfer liquid is indirect liquid contact with the patient's body to promote heat transferbetween the patient's body and said heat transfer liquid; and said lowermember having at least one outlet in fluid communication with theinterior space of the enclosure for exhausting said heat transfer liquidfrom the enclosure.
 2. An apparatus as set forth in claim 1 comprising aplurality of said inlets.
 3. An apparatus as set forth in claim 2wherein all of said plurality of inlets are located in said uppermember.
 4. An apparatus as set forth in claim 3 wherein the inlets arespread apart over the upper member.
 5. An apparatus as set forth inclaim 1 comprising a plurality of said outlets.
 6. An apparatus as setforth in claim 5 wherein all of said plurality of outlets are positionedon said lower member.
 7. An apparatus as set forth in claim 6 whereinthe outlets are spread apart over the lower member.
 8. An apparatus asset forth in claim 1 wherein said upper and lower members are engagableto form a substantially sealed enclosure.
 9. An apparatus as set forthin claim 1 wherein said lower member comprises a sheet and said uppermember comprises a sheet.
 10. An apparatus as set forth in claim 1wherein said enclosure further comprises an opening for permittingaccess to the patient during operation of the apparatus.
 11. Anapparatus as set forth in claim 10 wherein said opening is located onsaid upper member.
 12. Apparatus for adjusting the body temperature of apatient in a supine position, said apparatus comprising: an impermeableupper member for placement above the patient's body; an impermeablelower member for placement beneath the patient's body; said lower memberbeing engageable with said upper member to form an interior space forreceiving a portion of a patient's body from the neck of the patientdownward, including the torso, arms, and legs of the patient; said lowermember having a foot end and a head end spaced longitudinally from thefoot end for disposition nearer to the patient's head than said footend, the lower member having at least one inlet being disposedintermediate the foot and head ends and closer to said head end thansaid foot end, the inlet opening directly into said interior space sothat the inlet is in fluid communication with the interior space forreceiving heat transfer liquid into said interior space for directliquid contact with the patient's body to promote heat transfer betweenthe patient's body and said heat transfer liquid, at least one of saidupper member and said lower member having an outlet for exhausting saidheat transfer liquid from the enclosure.
 13. An apparatus as set forthin claim 12 wherein said inlet is positioned on a portion of the lowermember adapted for underlying the patient's body so that when thepatient's body is received in interior space of the enclosure thepatient's body overlies the inlet.
 14. Apparatus for adjusting the bodytemperature of a patient, said apparatus comprising: an upper member forplacement above the patient's body, the upper member having laterallyopposite sides; a lower member for placement beneath the patient's body,said lower member being engageable with said upper member to form aninterior space for receiving a portion of a patient's body; at least oneinlet for directing heat transfer liquid into said interior space toflow over the top of the patient's body towards the back of thepatient's body; said heat transfer liquid being in direct liquid contactwith the patient's body to promote heat transfer between the patient'sbody and said heat transfer liquid; and at least one outlet in fluidcommunication with the interior space of the enclosure for exhaustingsaid heat transfer liquid from the enclosure; said enclosure includingan opening sized and arranged for permitting access to the patientduring operation of the apparatus, said opening being one of at andadjacent to at least one of said sides of the upper member.
 15. Anapparatus as set forth in claim 14 wherein said opening is sealable forsubstantially sealingly enclosing said portion of the patient's body.16. An apparatus as set forth in claim 15 further comprising a pivotableflap for closing said opening.
 17. An apparatus as set forth in claim 14wherein said opening is located in said upper member.
 18. Apparatus foradjusting the body temperature of a patient, said apparatus comprising:an upper member for placement above the patient's body; a lower memberfor placement beneath the patient's body and engageable with said uppermember to form an interior space for receiving a portion of a patient'sbody; at least one inlet in fluid communication with the interior spacefor receiving heat transfer liquid into said interior space for directliquid contact with the patient's body to promote heat transfer betweenthe patient's body and said heat transfer liquid; and at least oneoutlet in fluid communication with the interior space for exhaustingsaid heat transfer liquid from the interior space; said lower memberincluding a liquid impermeable outer layer and a porous inner layerengageable with said portion of the patient's body for carrying saidheat transfer liquid.
 19. An apparatus as set forth in claim 18 whereinsaid porous layer comprises a layer of batting.
 20. An apparatus as setforth in claim 18 wherein said upper member comprises a liquidimpermeable outer layer and a porous inner layer capable of carryingsaid heat transfer liquid.
 21. An apparatus as set forth in claim 20wherein said porous layer of the upper member comprises a layer ofbatting.
 22. An apparatus as set forth in claim 18 at least a portion ofthe upper member is transparent for viewing a part of the portion of thepatient's body received in the interior space.
 23. An apparatus as setforth in claim 22 wherein the entire upper member is transparent.
 24. Anapparatus as set forth in claim 23 wherein said transparent upper memberis formed from a material selected from a group of materials includingpolyvinyl chloride, polyethylene, and polyurethane.
 25. An apparatus asset forth in claim 18 wherein said upper member has an opening foraccessing the interior space.
 26. An apparatus as set forth in claim 25wherein said opening is sealable for substantially sealingly enclosingsaid portion of the patient's body.
 27. An apparatus as set forth inclaim 18 wherein said inlet is positioned on said upper member fordirecting heat transfer liquid into said interior space to flow over thetop of the patient's body towards the back of the patient's body.
 28. Anapparatus as set forth in claim 27 wherein said inlet comprises aplurality of inlets for directing the flow of heat transfer fluid over alarger area of the enclosed portion of the patient's body.
 29. Anapparatus as set forth in claim 28 wherein said outlet comprises aplurality of outlets in said lower member.
 30. An apparatus as set forthin claim 27 wherein said upper member comprises a sheet-like body-facingcomponent and a sheet-like outer component, said sheet-like body-facingcomponent and sheet-like outer component being adapted for face-to-faceengagement with one another, said components further being joined to oneanother along their facing sides to form at least one liquid passagebetween the components, said liquid passage being shaped and sized forfluid communication with said inlet for receiving liquid, saidbody-facing component having at least one opening therein correspondingto the liquid passage for allowing liquid to pass from the liquidpassage to between the body-facing component and the portion of thepatient's body.
 31. An apparatus as set forth in claim 30 wherein saidcomponents are transparent.
 32. An apparatus as set forth in claim 18wherein said heat transfer liquid has a temperature in a range fromabout 1° C. (34° F.) to about 2° C. (36° F.).
 33. Apparatus foradjusting the body temperature of a patient, said apparatus comprising:an upper member for placement above the patient's body; a lower memberfor placement beneath the patient's body and engageable with said uppermember to form an interior space for receiving a portion of a patient'sbody; at least one inlet in fluid communication with the interior spacefor receiving heat transfer liquid into said interior space for directliquid contact with the patient's body to promote heat transfer betweenthe patient's body and said heat transfer liquid; and at least oneoutlet in fluid communication with the interior space for exhaustingsaid heat transfer liquid from the interior space; said upper memberincluding a sheet-like body-facing component and a sheet-like outercomponent, said sheet-like body-facing component and sheet-like outercomponent being adapted for face-to-face engagement with one another,said components further being joined to one another along their facingsides to form at least one liquid passage between the components, saidliquid passage being shaped and sized for fluid communication with saidinlet for receiving liquid, said body-facing component having at leastone opening therein corresponding to the liquid passage for allowingliquid to pass from the liquid passage to between the body-facingcomponent and the portion of the patient's body.
 34. An apparatus as setforth in claim 33 wherein said upper member further comprises a porouslayer capable of carrying said heat transfer liquid throughout theenclosure.
 35. An apparatus as set forth in claim 34 wherein said porouslayer of the upper member comprises a layer of batting.
 36. An apparatusas set forth in claim 33 wherein said opening comprises a plurality ofopenings for directing the flow of heat transfer fluid over a largerarea of the enclosed portion of the patient's body.
 37. An apparatus asset forth in claim 33 wherein said components are transparent.
 38. Anapparatus as set forth in claim 33 wherein said upper member has anopening for accessing the interior space of the enclosure.
 39. Anapparatus as set forth in claim 33 wherein said liquid passagescomprises a plurality of passages.
 40. Apparatus for adjusting the bodytemperature of a patient, said apparatus comprising: an upper member forplacement above the patient's body; a lower member for placement beneaththe patient's body and engageable with said upper member to form aninterior space for receiving a portion of a patient's body, said uppermember being smaller than the lower member thereby allowing forengagement of the lower member laterally inwardly from a peripheral edgeof the lower member; at least one inlet in fluid communication with theinterior space for receiving heat transfer liquid into said interiorspace for direct liquid contact with the patient's body to promote heattransfer between the patient's body and said heat transfer liquid; andat least one outlet in fluid communication with the interior space forexhausting said heat transfer liquid from the interior space.
 41. Anapparatus as set forth in claim 40 wherein at least a portion of theupper member is transparent.
 42. An apparatus as set forth in claim 41wherein the entire upper member is transparent.
 43. An apparatus as setforth in claim 40 wherein at least a portion of the lower member istransparent.
 44. An apparatus as set forth in claim 43 wherein theentire lower member is transparent.
 45. An apparatus as set forth inclaim 40 wherein said upper member comprises an opening for accessingthe interior space.
 46. An apparatus as set forth in claim 45 whereinsaid opening is sealable for substantially sealingly enclosing saidportion of the patient's body.
 47. An apparatus as set forth in claim 40wherein said transparent portion is formed from a material selected froma group of materials including polyvinyl chloride, polyethylene, andpolyurethane.
 48. An Apparatus as set forth in claim 40 wherein saidheat transfer liquid has a temperature in a range from about 1° C. (34°F.) to about 2° C. (36° F.).
 49. Apparatus for adjusting the bodytemperature of a patient, said apparatus comprising at least onesheet-like component sized and shaped for defining an interior space forreceiving a portion of a patient's body, said at least one sheet-likecomponent including a liquid passage configured to receive and directheat transfer liquid within the sheet-like component, an inlet forreceiving heat transfer liquid into the liquid passage, and at least oneopening separate from the inlet and in fluid communication with theliquid passage and the interior space of said apparatus to allow heattransfer liquid to flow from the liquid passage into said interior spacefor direct liquid contact with the portion of the patient's body topromote heat transfer between the patient's body and said heat transferliquid.
 50. Apparatus for adjusting the body temperature of a patient ina supine position, said apparatus comprising: an impermeable uppermember for placement above the patient's body; an impermeable lowermember for placement beneath the patient's body, said lower member beingengageable with said upper member to form an interior space forreceiving a portion of a patient's body from the neck of the patientdownward, including the torso, arms, and legs of the patient; said uppermember having a first end, a second end spaced longitudinally from thefirst end, and at least one inlet being disposed on the upper memberintermediate the first and second ends such that the at least oneopening is disposed adjacent the torso of the patient when the patientis received in the interior space, the inlet opening directly into saidinterior space and being configured for directing heat transfer liquidinto said interior space to flow over the top of the patient's bodytowards the back of the patient's body so that said heat transfer liquidis in direct liquid contact with the patient's body to promote heattransfer between the patient's body and said heat transfer liquid; andsaid lower member having at least one outlet in fluid communication withthe interior space of the enclosure for exhausting said heat transferliquid from the enclosure.